15 Puzzle

• Spatial
• Regions

Slide the numbered tiles until ascending order is restored, from the classic 4×4 board up to 7×7.

1. You may move only a tile adjacent to the empty space.
2. Arrange all numbered tiles from left to right and top to bottom, leaving the empty space in the lower-right corner.
3. Every Blupoli position is solvable; board size changes the number of tiles and difficulty changes the logical distance of the starting position.

• Solve the top edge first without undoing it; the last two rows require moving groups, not isolated tiles.
• Build the upper rows first and avoid breaking blocks that are already correctly placed.
• The empty space is your tool: plan where it needs to end before moving an important tile.
• Use Undo to explore an idea without losing the previous position.

Sliding-tile puzzles became popular in the nineteenth century; larger boards retain the same challenge of ordering pieces using one empty space.

• Build the upper rows first and avoid breaking blocks that are already correctly placed.
• The empty space is your tool: plan where it needs to end before moving an important tile.
• Use Undo to explore an idea without losing the previous position.

• Where should I begin? Solve the top edge first without undoing it; the last two rows require moving groups, not isolated tiles.
• What makes this game different? Every Blupoli position is solvable; board size changes the number of tiles and difficulty changes the logical distance of the starting position.